To understand a complex system like a mind or an ecosystem, we have to understand a tangled web of objects, features, processes, relations, correlations, clusters, constraints, causes, and so on. It helps to find underlying explanations and generating process, and to find deep reasons that explain why many relationships are the way they are. To find those underlying explanations, it helps to know relationships between relationships: which relationships cause, explain, or constrain other relationships. When staring at an assembly of relationships and asking which relationships explain other relationships, it can seem like we're at a loss for where to go; sometimes there are clearly relationships, but there's no clear way to extract any further order, because there's no basis on which to say that one relationship explains another——the relationships are just there, and that's it. By way of example/analogy, suppose we look at a list of facts like [3×4=12, 12/4=3, 4=12/3, 1...